An array substrate usually comprises a thin film transistor (TFT) and a storage capacitor. In the related art, in order to simplify the preparation process and reduce the number of patterning processes using a mask, a semiconductor pattern is usually formed in a region where a storage capacitor is required through the same patterning process while forming an active layer of a semiconductor material. And then, ion doping is performed on the semiconductor pattern so as to convert it from a semiconductor to a conductive material having a conductive property, thereby serving as one of the electrodes of the storage capacitor.
However, the electrode has a poor conductivity as it is formed of a semiconductor through ion doping, rather than being formed of metal material, and the performance of the storage capacitor is adversely affected.